Add Claude integration to dashboard

Add comprehensive Claude Code monitoring and realtime streaming to the K8s dashboard.
Includes API endpoints for health, stats, summary, inventory, and live event streaming.
Frontend provides overview, usage, inventory, debug, and live feed views.

dashboard/internal/claude/eventhub.go

@@ -0,0 +1,85 @@
+package claude
+
+import (
+	"sync"
+	"sync/atomic"
+	"time"
+)
+
+type EventHub struct {
+	mu          sync.RWMutex
+	buffer      []Event
+	nextID      int64
+	subscribers []chan Event
+	bufferSize  int
+}
+
+func NewEventHub(bufferSize int) *EventHub {
+	return &EventHub{
+		buffer:      make([]Event, 0, bufferSize),
+		subscribers: make([]chan Event, 0),
+		bufferSize:  bufferSize,
+	}
+}
+
+func (h *EventHub) Publish(ev Event) Event {
+	if ev.ID == 0 {
+		ev.ID = atomic.AddInt64(&h.nextID, 1)
+	}
+	if ev.TS.IsZero() {
+		ev.TS = time.Now()
+	}
+
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
+	if len(h.buffer) >= h.bufferSize {
+		h.buffer = h.buffer[1:]
+	}
+	h.buffer = append(h.buffer, ev)
+
+	for _, ch := range h.subscribers {
+		select {
+		case ch <- ev:
+		default:
+		}
+	}
+
+	return ev
+}
+
+func (h *EventHub) Subscribe() (chan Event, func()) {
+	ch := make(chan Event, 10)
+
+	h.mu.Lock()
+	defer h.mu.Unlock()
+
+	h.subscribers = append(h.subscribers, ch)
+
+	cancel := func() {
+		h.mu.Lock()
+		defer h.mu.Unlock()
+		for i, c := range h.subscribers {
+			if c == ch {
+				h.subscribers = append(h.subscribers[:i], h.subscribers[i+1:]...)
+				close(ch)
+				break
+			}
+		}
+	}
+
+	return ch, cancel
+}
+
+func (h *EventHub) ReplaySince(lastID int64) []Event {
+	h.mu.RLock()
+	defer h.mu.RUnlock()
+
+	var result []Event
+	for _, ev := range h.buffer {
+		if ev.ID > lastID {
+			result = append(result, ev)
+		}
+	}
+	return result
+}